The most commonly consumed vitamin and mineral supplements provide no consistent health benefit or harm, suggests a new study led by researchers at St. Michael's Hospital and the University of Toronto.

Multivitamins, vitamin D, calcium and vitamin C - the most common supplements - showed no advantage or added risk in the prevention of cardiovascular disease, heart attack, stroke or premature death. 

"We were surprised to find so few positive effects of the most common supplements that people consume," said Dr. David Jenkins, the study's lead author. "Our review found that if you want to use multivitamins, vitamin D, calcium or vitamin C, it does no harm - but there is no apparent advantage either."

"These findings suggest that people should be conscious of the supplements they're taking and ensure they're applicable to the specific vitamin or mineral deficiencies they have been advised of by their healthcare provider," Dr. Jenkins said.

"In the absence of significant positive data - apart from folic acid's potential reduction in the risk of stroke and heart disease - it's most beneficial to rely on a healthy diet to get your fill of vitamins and minerals," Dr. Jenkins said. "So far, no research on supplements has shown us anything better than healthy servings of less processed plant foods including vegetables, fruits and nuts." – Science Daily